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DS-102
Dual Channel RS-232 Asynchronous
Communications Adapter
for ISA compatible machines
INTERFACE CARDS FOR IBM PC/AT AND PS/2
User's Manual
QUATECH, INC. TEL: (330) 434-3154
662 Wolf Ledges Parkway FAX: (330) 434-1409
Akron, Ohio 44311 BBS: (330) 434-2481
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Table of Contents 1 I. GENERAL INFORMATION 2 II. INSTALLATION 4 III. ENABLING AND ADDRESSING PORTS 4 Setting the address 6 Enabling or disabling ports 8 IV. SETTING INTERRUPT LEVELS (IRQS) 9 Interrupt Sharing 10 V. EXTERNAL CONNECTIONS 14 VI. SERIAL PORT FUNCTIONAL DESCRIPTION 15 Accessing the Serial Port registers 16 INTERRUPT ENABLE REGISTER 16 INTERRUPT IDENTIFICATION REGISTER 18 FIFO CONTROL REGISTER (16550 only) 19 LINE CONTROL REGISTER 20 MODEM CONTROL REGISTER 21 LINE STATUS REGISTER 22 M
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WARRANTY INFORMATION Quatech, Inc. warrants the DS-102 to be free of defects for one (1) year from the date of purchase. Quatech, Inc. will repair or replace any board that fails to perform under normal operating conditions and in accordance with the procedures outlined in this document during the warranty period. Any damage that results from improper installation, operation, or general misuse voids all warranty rights. Please complete the following information and retain for your rec
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© 1993, Quatech, Inc. NOTICE The information contained in this document cannot be reproduced in any form without the written consent of Quatech, Inc. Likewise, any software programs that might accompany this document can be used only in accordance with any license agreement(s) between the purchaser and Quatech, Inc. Quatech, Inc. reserves the right to change this documentation or the product to which it refers at any time and without notice. The authors have taken due care in the preparation o
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I. GENERAL INFORMATION The Quatech, Inc. DS-102 provides two RS-232 asynchronous serial communication interfaces for IBM-compatible personal computer systems using the ISA (Industry Standard Architecture) expansion bus. The DS-102's two serial ports are implemented using 16450 Universal Asynchronous Receiver/Transmitters (UARTs). For higher performance, 16550 UARTs can be installed in place of the 16450 UARTs. The 16550 contains a hardware buffer that reduces processing overhead. Software must
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II. INSTALLATION If the default address and interrupt settings are sufficient, the DS-102 can be quickly installed and put to use. The factory defaults are listed in Figure 1. PORT ADDRESS IRQ ENABLED ? Serial 1 3F8 hex (COM1) 4 YES Serial 2 2F8 hex (COM2) 3 YES Figure 1 --- Default address and IRQ settings for DS-102 The serial port outputs on the DS-102 are CN1 and CN2, which are shielded D-9 connectors. Serial 1 is available on CN1 and Serial 2 is available on CN2. 1. If the default setti
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Set addresses here (SW1, SW2) (Diagram not to scale) 16450/16550 CN1 J1 J7 Serial 1 16450/16550 J2 SW1 SW2 J4 J3 Serial 1 Serial 2 Serial 2 J8 Serial 1 J5 Serial 2 J6 CN2 QUATECH INC. DS-102 Set IRQ levels here (J5, J6) Figure 2 --- Diagram of DS-102 Quatech DS-102 User's Manual 3 IRQ2 IRQ3 IRQ4 IRQ5 IRQ6 IRQ7
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III. ENABLING AND ADDRESSING PORTS Setting the address Each serial port on the DS-102 uses 8 consecutive I/O locations in the range of 0000 hex to 07FF hex. The base address of each port is set using a DIP switch pack on the DS-102. When setting the address selection switches, a switch in the "ON" position specifies that the corresponding address line must be a logic 0 for the port to be selected. Similarly, a switch in the "OFF" position forces the corresponding address line to be a logic 1
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Switch on Switch off Serial 1 uses SW1 bit = 1 bit = 0 Serial 2 uses SW2 Factory default setting for Serial 1 --- 03F8 hex (COM1) SW1 ON 1 2 3 4 5 6 7 8 2 1 8 2 1 8 0 4 3 F 8 Factory default setting for Serial 2 --- 02F8 hex (COM2) SW2 ON 1 2 3 4 5 6 7 8 8 2 1 8 0 2 0 4 2 F 8 Example: 03E8 hex (typical for COM3) ON 1 2 3 4 5 6 7 8 8 0 2 1 8 4 2 0 3 E 8 Example: 02E8 hex (typical for COM4) ON 1 2 3 4 5 6 7 8 0 2 0 8 4 2 0 8 2 8 E Figure 4 --- Serial Port base I/O address selection switches Q
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The standard addresses for serial ports COM1 and COM2 are listed in Figure 5. Recommended addresses for serial ports COM3 and COM4 are also listed. The switch settings for these addresses are shown in Figure 4. PORT TYPICAL I/O ADDRESS NOTES COM1 03F8 hex Factory default for Serial 1. COM2 02F8 hex Factory default for Serial 2. COM3 03E8 hex Recommendations only. No official standards exist for COM3 and COM4. COM4 02E8 hex Figure 5 --- Recommended addresses for serial ports Enabling or disab
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IV. SETTING INTERRUPT LEVELS (IRQS) The DS-102 interrupt circuitry allows each port to use any interrupt level in the range IRQ2 through IRQ7. The interrupt levels are selected using jumper packs J5 for Serial 1 and J6 for Serial 2. In Figure 7, the factory default settings for Serial 1 and Serial 2 are shown. Serial 1 J5 Default is IRQ 4 Serial 2 J6 Default is IRQ 3 Figure 7 --- Interrupt level (IRQ) selection 8 Quatech DS-102 User's Manual IRQ2 IRQ2 IRQ3 IRQ3 IRQ4 IRQ4 IRQ5 IRQ5 IRQ6 IRQ6 I
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Interrupt Sharing An interrupt sharing circuit allows a port on the DS-102 to share an interrupt with the other port on the board or with another Quatech adapter supporting sharable interrupts. When interrupt sharing is used, the software must query each port attached to a given IRQ level when an interrupt for that IRQ is received by the computer. Use of this feature is beyond the capabilities of most commercial applications. If the software to be used with the DS-102 is not specially written
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V. EXTERNAL CONNECTIONS RS-232-C devices are classified by their function as either Data Terminal Equipment (DTE) or Data Communication Equipment (DCE). Generally, data terminal equipment is defined as the communication source and data communication equipment is defined as the device that provides a communication channel between two DTE-type devices. Terminal Modem RS-232-C DTE DCE Telephone line Terminal Modem RS-232-C DTE DCE Figure 10 --- Use of DTEs and DCEs in a communications link DTE- and
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To simplify connections to other devices, each port on the DS-102 is equipped with a jumper block that allows the port to be configured as either a DTE- or DCE-type device. This allows the DS-102 to communicate with either DTE- or DCE-type devices without using a null modem cable. J7 is used for Serial 1 and J8 is used for Serial 2. The DTE/DCE selection jumper blocks are illustrated in Figure 12. pin 3 TxD 1 7 J7 -- Serial 1 2 8 pin 2 RxD J8 -- Serial 2 These jumper blocks are used to 3 9
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The DS-102 connects to peripheral equipment through male D-9 connectors. Adapters are available to convert these connectors into standard D-25 male connectors. The standard serial port connections are listed in Figure 13. RS-232 Signal DTE Connection DCE Connection Description D-9 D-25 D-9 D-25 Data Carrier Detect (DCD) 1 8 1 8 Receive Data (RxD) 2 3 3 2 Transmit Data (TxD) 3 2 2 3 Data Terminal Ready (DTR) 4 20 6 6 Signal Ground 5 7 5 7 Data Set Ready (DSR) 6 6 4 20 Request To Send (RTS) 7 4
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VI. SERIAL PORT FUNCTIONAL DESCRIPTION This section contains information intended for advanced users planning to do custom programming with the DS-102. The information presented here is a technical description of the interface to the 16450 or 16550 UART. The 16450 UART is an improved functional equivalent of the 8250 UART, performing serial-to-parallel conversion on received data and parallel-to-serial conversion on output data. Designed to be compatible with the 16450, the 16550 UART enters c
